Treatment fluids can be employed in a variety of subterranean operations. As used herein the terms “treatment,” “treating,” other grammatical equivalents thereof refer to any subterranean operation that uses a fluid in conjunction with performing a desired function and/or for achieving a desired purpose. The terms “treatment,” “treating,” and other grammatical equivalents thereof do not imply any particular action by the fluid or any component thereof. Illustrative subterranean operations that can be performed using treatment fluids can include, for example, drilling operations, fracturing operations, sand control operations, gravel packing operations, acidizing operations, conformance control operations, fluid diversion operations, fluid blocking operations, and the like.
Treatment for fluid-loss control can be used during any of drilling, completion, and intervention operations. During completion or intervention, stimulation is a type of treatment performed to enhance or restore the productivity of oil or gas from a well. Stimulation treatments fall into two main groups: hydraulic fracturing and matrix treatments. Fracturing treatments are performed above the fracture pressure of the subterranean formation to create or extend a highly permeable flow path between the formation and the wellbore. Matrix treatments are performed below the fracture pressure of the formation. Other types of completion or intervention treatments can include, for example, gravel packing, consolidation, and controlling excessive water production, and controlling sand or fines production. Still other types of completion or intervention treatments include, but are not limited to, damage removal, formation isolation, wellbore cleanout, scale removal, and scale control.
Different types of “lost circulation materials” (hereinafter “LCM”) may be used. These include cellulose and chitin. Cellulose is the world's most abundant biopolymer on earth. It is natural, renewable, and biodegradable. It is synthesized by plants as well as by some specialized bacteria. Its molecular structure is constituted by a linear backbone of β-1, 4-O-glycosyl linked D-glucose residues bundled up in a microfiber. The cellulose microfiber varies in length depending on the cellulose species.
Chitin is a natural biopolymer material found in the protective exoskeletons of arthropods (insects, spiders, crustaceans such as crab, shrimp, etc.). Exoskeletons represent a natural composite material having a hierarchical structure containing proteins and minerals along with chitin. This chitin provides reinforcement of the protein matrix in the arthropods' shells.
Cellulose, chitin and its derivative chitosan have been used in certain drilling applications, such as an additive to drilling fluids. However, such applications have either utilized small particles of the cellulose fibers or chitin shells without regard to the nanofiber physical composition or arrangement. Accordingly, such methods have not made the most beneficial use of cellulose, chitin or chitosan.